Water-Transporting System in Higher Plants and Its Elements: 6. Relationship between Root Pressure and Transpiration in an Intact Plant

Water-Transporting System in Higher Plants and Its Elements: 6. Relationship between Root...
Meleshchenko, S.
2004-10-13 00:00:00
Novel experimental data were adapted to a previously devised concept of water relations in plant roots. The improved concept explains the formation in the root stele of a high water potential that exceeds the water potential of the root environment. The physical basis of this phenomenon relies on active metabolism of the peripheral root zone (cortex) and, more importantly, on the unloading of assimilates from the root central cylinder (stele) to the outer cylinder (cortex). The unloading not only raises the water potential of the root stele but also increases the hydraulic resistance; these two factors account for the elevation of root pressure. The process of unloading assimilates from the root stele to the cortex is apparently promoted by the transit of the ascending water flow through the cortex. This flow, enriched with the dissolved oxygen of the root environment, stimulates the unloading and metabolic conversion of assimilates in the root symplast.
http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.pngRussian Journal of Plant PhysiologySpringer Journalshttp://www.deepdyve.com/lp/springer-journals/water-transporting-system-in-higher-plants-and-its-elements-6-s89k6n6r7S

Water-Transporting System in Higher Plants and Its Elements: 6. Relationship between Root Pressure and Transpiration in an Intact Plant